Yes, stress can certainly interfere with a man's (and a woman's) ability to perform sexually. The mind and body make priorities. Stress activates the defense against danger. This causes priority to fight and run. If you are obsessed by thoughts about the stresses of the day, this prevents you from thinking of love and tenderness. If a person is aware of the problems, and how they can be solved, the stress can be reduced.
In the work place, a person is often prevented from expressing anger or anxiety. When coming home, the frustrated feelings may be vented towards the family members. When this happens, try to share his or her stress, so that you are a partner and not an object of his stress and anger. Ask about all his problems and worries. Allow him to vent his feelings, to cry about all that is difficult at work. After crying comes a need for comfort, and comfort can turn into tenderness and lovemaking. Lovemaking can then become a way of relieving stress.
Paradoxically, certain kinds of stress can also intensify sexual behaviour. It is well-known that the birth rate goes up during war. The baby boom during the second world war is still visible in the age distribution of the population in affected countries. And there are people who seek out so-called adventerous sex in unusual surroundings.
The difference is if you are in control of the situation. Studies show that stress increases sexual activity for the dominant male, but reduces it for the non-dominant males.